<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>

    <style>
        th,td {
            border: 1px solid #ccc;
            text-align: center;
        }

        table {
            border: 1px solid #ddd;
            margin: 100px auto;
            width: 450px;
        }
    </style>
</head>

<body>
    <div id="app">
        <table>
            <caption>欢迎光临_vue开发的收银系统_水果店</caption>
            <tr>
                <th>苹果10￥ / 斤，折扣 &lt; 8折 &gt; </th>
            </tr>
            <tr>
                <td>请输入你要购买的斤数 <input v-model="count" type="number"></td>
            </tr>
            <tr>
                <td>
                    <button @click="checkout">结账买单~</button>
                </td>
            </tr>
            <tr>
                <td>结账单：总价：{{ total }} ￥元 折后价：{{ total * .8 }}￥元 省了：{{ total * .2}}￥元</td>
            </tr>
        </table>
    </div>

    <script src="./vue.js"></script>
    <script>
        new Vue({
            el: '#app',
            data: {
                count: 0,
                // 保存总价
                total: 0,
            },
            methods: {
                checkout () {
                    // 要用数量 * 单价 得到总价，赋值给total
                    this.total = this.count * 10
                }
            }
        })
    </script>
</body>

</html>